We've often seen southbound male Pectoral Sandpipers with obvious "sacs" in
southern Ontario (Toronto - Lake Ontario) in mid-July. Male Pectorals
migrate south before the females (females first in most shorebirds) when
the young hatch. Some July males we've seen show a sagging lower neck bib
(stretch marks), evidence that they recently were courting males. If you
watch Pectorals closely this July, you should see some males still showing
signs of sacs from immensely inflating their throats in courtship.
Ron Pittaway & Jean Iron
Toronto & Minden
At 09:57 PM 6/23/2006 -0400, you wrote:
>Frode Falkenberg asked, "Is it known if Pectoral Sandpipers migrate with
>developed breast sacs?" I cannot claim scientific expertise with regard to
>this species, and never having been on its breeding grounds, I have no idea
>what proportion leave the breeding grounds with a conspicuous pectoral sac.
>I can report that of the very many Pectorals that I have observed
>over about 25 years on the northeast coast of the USA only one had a very
>highly developed, conspicuous, bulging and dangling pectoral sac. That
>striking individual was observed on July 31, 1990, on a barrier island off
>the south shore of Long Island, specifically
>at the Cedar Beach Overlook area in Suffolk County, New York.
>Westbury, Long Island, NY
>----- Original Message -----
>From: "Frode Falkenberg" <[log in to unmask]>
>To: <[log in to unmask]>
>Sent: Thursday, June 22, 2006 4:51 PM
>Subject: [BIRDWG01] Pectoral sac
> > Hi all!
> > A little background for the upcoming question: An adult Pectoral Sandpiper
> > found today near Bergen in western Norway. It was located in a marsh on
> > outer coastline, where species such as Common Snipe, Eurasian Curlew and
> > Redshank breed commonly. There are no Calidris-species breeding there. It
> > actually seen when chasing two Common Snipes.
> > The bird has developed a big sac in its breast. All info I can find links
> > feature to males at their breeding grounds, used to make their
> > booming-sounds.
> > Have a look at the bird and its sac here:
> > <http://cyberbirding.uib.no/photo/c_melanotos_02.php>
> > My questions are: Is it known if Pectoral Sandpipers migrate with
> > breast sacs? Could this indicate that the bird is territorial? Do first
> > males develope such sacs?
> > All the best,
> > Frode Falkenberg
> > www.cyberbirding.no
> > Join or Leave BIRDWG01:
> > Archives: http://listserv.arizona.edu/archives/birdwg01.html
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